[Mailman-Users] Whitelisting & Blacklisting domains

[Edward Ned Harvey]

I am configuring a company private mailman server, where we want people
inside the company to be able to subscribe and unsubscribe freely... And
block any attempts from anyone outside the company.

Is there some whitelisting/blacklisting/pattern matching capability, to
automatically accept subscriptions from within the company and deny from
outside?